Holder for the glowers of tungsten lamps



UNHTED STATES PATaNr orrlce.

oTTo scHALLnR, F sunnnnn, NEAR BERLIN, GERMANY, ASSIGNOR To rmmwnniosrnvTscn or BERLIN, GERMANY.

HOLDER non. Tnn enownns on TUivGsTEn. LAMPS;

No Drawing;

(GRANTED UNDER Tim rnovrsrons or Tnn'AcT 01? MARCH 3, 1921, 41 STAT. n,1313.

T 0 all whom it may concern:

Be it known that I, OTTO ScHALLnR, a subject of the Emperor of Germany,residing at Siidende, near Berlin, Germany, have in- 5 vented certainnew and useful Improvements in a Holder for the Glowers oi TungstenLamps, (for which I have filed an application in Germany January 30,1915,) of which the following-is a specification.

In tungsten lamps, loaded with 0.5-0.8 watt per candle, the so-calledhalf-a-watt lamps, wires of molybdenum or tungsten are made use of forholding the filament wound up to a spiral. On account of the very hightemperature, to which the filament is exposed, it becomes necessary togive these holding wires such a thickness that they cannot become toohot. But too strong a heating has'the consequence that the holdersbecome soft and get deformed either by their owngravity or by the weightofthe glower, the consequence being that in most cases the glow-lampwill become useless. The use of very thin holders is, from such reason,not possible. Now, thick wires have the enormous drawback of withdrawingfromthe filament very much energy in form of heat. This quantity ofenergy is not only used to no purpose, it produces also a noxious heat-.30 ing of the whole bulb. This cooling of the filament is to beremarked in the most disagreeable manner with half-a-watt lamps of lowcandle-power of standard pressures of 110 and 220 volts. Though theselamps radiate a dazzling, white light, their consumption of energy percandle is in most cases far above 0.5 watt.

The present invention avoids this inconvenience and permits also ofmanufacturing lamps of a low candle power for standard pressures of 110and 220 volts witha specificconsumption of energy of 0.5 watt percandle. It is based upon the observation that tungsten wires having anaddition of 14% of thoriumoxid remain, contrary to wires of tungsten ormolybdenum, even in the highest Specification of Letters Patent..Paiientd D ec, 13, 1921., i I

Application filed. October 27, 1916. Serial No. 128,100;'

white-heat hard and rigid, whereas at low temperatures they are soft andflexible so,

that they may be worked with ease. Consequently such wires constitute anexcellent ma terial for making the holders of filaments.

They resist to all temperatures to be considered and may be taken sothin that they do not withdraw any appreciable quantity of energy fromthe filament. They may even be thinner than the glowing filament itself.7

What I claim as my invention and desire to secure by 'United StatesLetters Patent is A holder for metallic filament lamps ofa low specificconsumption of energy, thereby substantially as set forth and for thepurpose specified. i

In testimony whereof, I afiix my signature in the presence of'twowitnesses.

V HENRY HASPER, LILL F ANK,

characterized that it consists of tungsten i with an addition of 1-4:%of thorium oxid,

